WASHINGTON (AP) — The Internal Revenue Service inappropriately flagged conservative political groups for additional reviews during the 2012 election to see if they were violating their tax-exempt status, a top IRS official said Friday.

Organizations were singled out because they included the words "tea party" or "patriot" in their applications for tax-exempt status, said Lois Lerner, who heads the IRS division that oversees tax-exempt groups.